1. Field of the Invention
The present invention relates to a solid-state image sensor, a method of manufacturing the same, and a camera.
2. Description of the Related Art
With the tendency toward increasing semiconductor chip size and increasing manufacturing process complexity, it has become possible to use a technique of separately manufacturing a plurality of substrates and connecting them by using bumps.
FIG. 2 in Japanese Patent Laid-Open No. 2008-85755 discloses a structure in which a pixel cell 16 and a reception circuit 17 are electrically connected to each other by forming a capacitance by using an electrode for outputting a signal from the pixel cell 16 to the reception circuit 17 and an electrode for inputting a signal from the pixel cell 16 to the reception circuit 17. In this case, the pixel cell 16 includes a photoelectric conversion portion, a transfer portion for transferring the charge generated in the photoelectric conversion portion, and an amplifier portion for amplifying a signal corresponding to the amount of charges. As disclosed in FIGS. 6 to 10 in Japanese Patent Laid-Open No. 2008-85755, the capacitance formed by the two electrodes may be disposed after the pixel cell 16 (after an inverter, multiplexer, or the like).
According to Japanese Patent Laid-Open No. 2008-85755, a solid-state image sensor is formed by combining a substrate (solid-state image sensor element 11) including the pixel cell 16 with a substrate (signal processing element 12) including the reception circuit 17. Photoelectric conversion portions, transfer portions, and amplifier portions are arranged on the substrate including the pixel cell 16, and hence it is difficult to increase the aperture ratio of each pixel while ensuring an area for each photoelectric conversion portion.